Powertrain Control Module (PCM)
WARNING: This page is about a different car, the 2005 Mercury Montego, 2005 Ford Freestyle, and 2005 Ford Five Hundred. However, it is still accessible from the selected car via links, so may be relevant.
The PCM uses the high speed CAN for communication with the diagnostic tool. The PCM controls the engine for better fuel economy, emissions control, failure mode detection and storage. For additional information, refer to the INTRODUCTION - GASOLINE article for diagnosis and testing of the PCM.